AbstractText simplification is a frequently used technique in language teaching. The use of reading texts for the target language in native language / secondary language education is the most important reason for text simplification. According to Krashen's comprehensible input theory, the fact that the linguistic input is ileri meaningful as makes the learners a natural member of the communication medium of the target language. This is possible with the linguistic input presented to learners one step ahead of the learner's knowledge. Therefore, it is ensured that reading texts, one of the linguistic input types, are part of the foreign / second language education / acquisition process with text simplification techniques. In this study, reading texts in Gazi University Turkish Teaching Set were investigated and the frequency of using authentic materials was investigated. It is determined that the texts created by authentic (original) and material developers are simplified in different directions according to the language levels. Texts have been simplified in terms of content, grammar, vocabulary, and syntax, based on language levels and targeted gains.